Methanosaeta thermophila: Difference between revisions
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<font size=12 color="Purple">●~Application to Biotechnology~</font> | <font size=12 color="Purple">●~Application to Biotechnology~</font> | ||
''Methanosaeta thermofiles are relevant for biotechnology, energy production, | ''Methanosaeta thermofiles are relevant for biotechnology, energy | ||
production, and as major manufacturers as biofuels. As methanogens, ''M. | |||
thermophila'' is a source of natural gas and could be useful producers of | |||
biofuels because they can metabolize acetate into methane by “reducing the | |||
methyl group to CH4 with electrons derived from oxidation of the carbonyl | |||
group to CO2,” (5). With biofuels, fuel is produced from various resources, | |||
such as plants, vegetable oils, and treated municipal and industrial wastes. | |||
The use of biofuels as a preservative to petroleum-based fuels can have the | |||
effect of burning with less discharge of carbon monoxide and pollutants, | |||
''Methanosaeta thermofiles'' are also contributors to biogas. Biogas is the product of the | helping to produce a cleaner environment. | ||
''Methanosaeta thermofiles'' are also contributors to biogas. Biogas | |||
is the product of the anaerobic breakdown of organic matter, such as sewage | |||
and waste products, by bacteria, which produce a mixture of methane and carbon | |||
dioxide. This reaction is important because biogases are used in the | |||
generation of hot water and electricity. | |||
<font size=12 color="Purple">●~Current Research~</font> | <font size=12 color="Purple">●~Current Research~</font> | ||
Although ''Methanosaeta'' continues to be comprehensively studied both biochemically and | Although ''Methanosaeta'' continues to be comprehensively studied both | ||
biochemically and genetically, studies have decreased due to its slow growth | |||
(up to 12 days doubling time) and lower growth yield than other microbes. | |||
One current study of this microbe by Alber, B.E. and Ferry J.G., determined | |||
that ''Methanosaeta thermofile'' archaea produce a carbonic anhydrase, which | |||
is an enzyme that catalyzes the reaction of water with carbon dioxide. The | |||
carbonic anhydrase(abbreviated CA) from acetate-grown ''Methanosaeta | |||
thermophila'' was purified. The molecular mass of the enzyme (CA) was | |||
determined via gel filtration chromatography. The results indicated that | |||
Another study detected central glutamates in the acetate kinase from the ''Methanosaeta | this particular CA represented a distinct class of CA’s and provided a | ||
foundation to determine the unique roles for CA in acetotrophic anaerobes. | |||
Another study detected central glutamates in the acetate kinase from | |||
the ''Methanosaeta thermophila''. Acetate kinase is an enzyme which catalyzes | |||
the reversible phosphorylation (adding a phosphate group) of acetate. The | |||
suggested mechanism denoted an unspecified glutamate residue was phosphorylated, | |||
and the “alignment of the amino acid sequences for the acetate kinases from | |||
E. coli (Bacteria domain), ''Methanosarcina thermophila'' (Archaea domain), | |||
and four other phylogenetically divergent microbes revealed high identity | |||
which included five glutamates,” (9). These glutamates were substituted in | |||
the ''M. thermophila'' enzyme to determine if they were required for catalysis. | |||
A third study explored new methods which permitted genetic analysis within the Archaea | The substituted enzymes were tagged and created in E. coli and purified by | ||
metal affinity chromatography. The substituted enzymes produced undetectable | |||
kinase activity. These results imply that the glutamates in the acetate | |||
kinase were in fact required for catalysis, which supports the original | |||
suggested mechanism. | |||
A third study explored new methods which permitted genetic analysis | |||
within the Archaea domain. Several separately, individually, replicating | |||
plasmid shuttle vectors were constructed. These vectors that were created | |||
were successful at replication in 9 of the 11 ''Methanosaeta'' strains tested. | |||
A method was created where DNA was brought in by liposomes, which permitted | |||
transformation. During the course of this study, the complete DNA sequence was | |||
determined. | |||
Revision as of 16:50, 5 June 2007
Methanosaeta thermophila
● ~Classification~
Organism Name: Methanosaeta thermophila PT
Domain: Archaea
Phylum: Euryarchaeota
Class: Methanomicrobia
Order: Methanosarcinales
Family: Methanosaetaceae
Genus: Methanosaeta
Species: Methanothrix thermophila
Genus Species Strain: Methanosaeta thermophila PT
Name History: Synonyms: Methanothrix thermophila PT
Methanothrix thermophila DSM 6194
Equivalent names: Methanosaeta thermophila strain PT
Methanosaeta thermophila str. PT
●~Description and Significance~
Methanosaeta thermophila are nonmotile, nonsporulating, and
thermophilic, which means they thrive at temperatures of 50ºC or higher.
This microbe was discovered by a molecular technique using fluorogenic
PCR polymerase chain reaction, which amplifies DNA) to identify its
methanotrophic and activity in marine anoxic microbial communities. This was
accomplished by identifying and quantifying the mcrA genes. Following
amplification, molecular analysis was performed by clone analysis of the 16S
rRNA and mcrA genes. The mcrA genes (encoding the methyl coenzyme M reductase,
specific to methanogenic archaea), are specific to the various phylogenetic
groups of methanotropic Archaea. Methanosaeta thermophila was identified
among the microbial communities in deep sediments and “methane seepages of
Omine Ridge in the Nankai Trough accretionary prism,” (1).
The addition of Methanosaeta to the methanoarchaeal genome
sequence compilation offered an opportunity to gain significant insight into
this intricate microbe and the unique use of comparative genomic approaches
allows one to address the nature of these specific microbes and their biological
influence and capability. Because these microbes are methanogens, they serve
an important role as the producers of natural gas and have potential as
creators of biofuels (fuels derived from a biomass).
●~Genome Structure~
The Methanosaeta thermophila’s genome has been entirely sequenced.
These microbes possess circular chromosomes and do not contain plasmids.
(The following genome sequence information, list, and map of the Methanosaeta
thermophila chromosome was taken from the eleventh source listed under the
references section.)
Genome Sequence: RS: NC_008553
Genome Sequence Length: 1879471
Statistics: Number of nucleotides: 1879471
Number of protein genes: 1696
Number of RNA genes: 51
Genome Statistics Number % of Total
DNA, total number of bases total 100.00%
DNA G+C number of bases 0.00%
DNA scaffolds 0 100.00%
Genes total number 0 100.00%
Protein coding genes 0 0.00%
RNA genes 0 0.00%
rRNA genes 0 0.00%
5S rRNA 0 0.00%
16S rRNA 0 0.00%
18S rRNA 0 0.00%
23S rRNA 0 0.00%
28S rRNA 0 0.00%
tRNA genes 0 0.00%
Other RNA genes 0 0.00%
Genes with function prediction 0 0.00%
Genes without function prediction 0 0.00%
Genes w/o function with similarity 0 0.00%
Genes w/o function w/o similarity 0 0.00%
Pseudo Genes 0 0.00%
Genes assigned to enzymes 0 0.00%
Genes connected to KEGG pathways 0 0.00%
Genes not connected to KEGG pathway 0 0.00%
Genes in ortholog clusters 0 0.00%
Genes in paralog clusters 0 0.00%
Genes in COGs 0 0.00%
Genes in Pfam 0 0.00%
Genes in TIGRfam 0 0.00%
Genes in InterPro 0 0.00%
Genes with IMG Terms 0 0.00%
Genes in IMG Pathways 0 0.00%
Obsolete Genes 0 0.00%
Revised Genes 0 0.00%
Pfam clusters 0 0.00%
Paralogous groups 0 100.00%
Orthologous groups 0 0.00%
●~Cell Structure and Metabolism~
Methanosaeta thermophila is circular (coccus), with one inner membrane
and one cell wall. This microbe does not interact with other organisms, grows
extremely slow, does not contain plasmids, does not possess flagella, but they
do however produce gas vacuoles to help them move in aquatic environments. Gas
vacuoles are cavities within the cytoplasm, which contain a gas similar to that
of their surrounding atmosphere. These vacuoles serve as floatation devices
because they decrease in size when subjected to increased hydrostatic pressure.
So although they are nonmotile, their gas vacuoles allow some degree of
flexibility in regards to how much movement they have in aquatic environments.
Methanosaeta thermophila obtain their energy as a “thermophilic
obligately-aceticlastic methane-producing archaeon,” which means that they
produce methane from acetate, (4). Although approximately two-thirds of all
methane is derived from the methyl group of acetate, Methanosaeta are able
to utilize acetate as a substrate for methanogenesis. Methanosarcina is
the only other genus of methanoarchaea that are capable of utilizing acetate
as a substrate, as well as using H2/CO2, dimethylsulfide, and and methanethiol
compounds as substrates. Unlike the faster-growing Methanosarcina, which
prefers methylated compounds to acetate, Methanosaeta is a slow-growing
specialist that utilizes acetate only.
●~Ecology~
The environment at which Methanosaeta thermophiles are found is
aquatic (living and growing in water) and they exhibit optimal growth between
55-60°C. Although they are present in many environments, such as anaerobic
digesters, anaerobic biofilms, sediments, and anaerobic sludges, they are
predominantly found in rice paddies, which allow a continuous stream of water
to flow through them. Acetate is the most important substrate for
methanogenesis in rice paddies and studies have shown that the concentration
of acetate in flooded rice paddies is in the 5-100 mM range, and Methanosaeta
thermophiles are the predominant acetate-utilizing methanoarchaea in these
aquatic rice paddies.
Methanosaeta species are the most prevalent methanogenic archaea of
the microbial population in numerous environments, including rough sludge
digesters, solid wastes, sewage slush,and anaerobic reactors. During activation
of anaerobic bioreactors, Methanosaeta species are widespread due to the
high acetate concentration. However, as bioreactors become stable and attain
their peak performance, the acetate concentration decreases, as well as the
Methanosaeta population.
●~Pathology~
Methanosaeta thermofilesare not pathogens and therefore are not disease causing microbes. To this date, there are no known archaea that are pathogens.
●~Application to Biotechnology~
Methanosaeta thermofiles are relevant for biotechnology, energy
production, and as major manufacturers as biofuels. As methanogens, M.
thermophila is a source of natural gas and could be useful producers of
biofuels because they can metabolize acetate into methane by “reducing the
methyl group to CH4 with electrons derived from oxidation of the carbonyl
group to CO2,” (5). With biofuels, fuel is produced from various resources,
such as plants, vegetable oils, and treated municipal and industrial wastes.
The use of biofuels as a preservative to petroleum-based fuels can have the
effect of burning with less discharge of carbon monoxide and pollutants,
helping to produce a cleaner environment.
Methanosaeta thermofiles are also contributors to biogas. Biogas
is the product of the anaerobic breakdown of organic matter, such as sewage
and waste products, by bacteria, which produce a mixture of methane and carbon
dioxide. This reaction is important because biogases are used in the
generation of hot water and electricity.
●~Current Research~
Although Methanosaeta continues to be comprehensively studied both
biochemically and genetically, studies have decreased due to its slow growth
(up to 12 days doubling time) and lower growth yield than other microbes.
One current study of this microbe by Alber, B.E. and Ferry J.G., determined
that Methanosaeta thermofile archaea produce a carbonic anhydrase, which
is an enzyme that catalyzes the reaction of water with carbon dioxide. The
carbonic anhydrase(abbreviated CA) from acetate-grown Methanosaeta
thermophila was purified. The molecular mass of the enzyme (CA) was
determined via gel filtration chromatography. The results indicated that
this particular CA represented a distinct class of CA’s and provided a
foundation to determine the unique roles for CA in acetotrophic anaerobes.
Another study detected central glutamates in the acetate kinase from
the Methanosaeta thermophila. Acetate kinase is an enzyme which catalyzes
the reversible phosphorylation (adding a phosphate group) of acetate. The
suggested mechanism denoted an unspecified glutamate residue was phosphorylated,
and the “alignment of the amino acid sequences for the acetate kinases from
E. coli (Bacteria domain), Methanosarcina thermophila (Archaea domain),
and four other phylogenetically divergent microbes revealed high identity
which included five glutamates,” (9). These glutamates were substituted in
the M. thermophila enzyme to determine if they were required for catalysis.
The substituted enzymes were tagged and created in E. coli and purified by
metal affinity chromatography. The substituted enzymes produced undetectable
kinase activity. These results imply that the glutamates in the acetate
kinase were in fact required for catalysis, which supports the original
suggested mechanism.
A third study explored new methods which permitted genetic analysis
within the Archaea domain. Several separately, individually, replicating
plasmid shuttle vectors were constructed. These vectors that were created
were successful at replication in 9 of the 11 Methanosaeta strains tested.
A method was created where DNA was brought in by liposomes, which permitted
transformation. During the course of this study, the complete DNA sequence was
determined.
